It is common medical practice to intravenously infuse various fluids or medicaments into a blood vessel of a patient (e.g., a vein or artery). Such infusion is typically accomplished by the insertion of a hollow introducer needle into a target blood vessel. The introducer needle is fluidly connected to one end of an elongate, flexible tube or fluid line, the opposite end of which is fluidly connected to a solution bag. The solution bag itself is typically suspended above the patient so as to allow gravity to facilitate the flow of fluid downwardly through the fluid line and into the patient's blood vessel via the introducer needle which remains operatively positioned therewithin. The fluid tube and solution bag are connected to each other via a metering apparatus which controls the infusion rate of fluid from the bag into the tube.
In many intravenous infusion assemblies, an injection site is fluidly coupled within the tubing intermediate the introducer needle and the solution bag. The injection site typically has a Y-shaped configuration and comprises a tubular main body portion having a tubular side arm portion in fluid communication therewith. The distal end of the side arm portion is fluidly connected to the solution bag via an upper segment of the tubing, with the bottom end of the main body portion being fluidly connected to the introducer needle via a lower segment of the tubing. The top end of the main body portion is itself covered by a diaphragm which is typically fabricated from rubber or a similar resilient material.
The inclusion of the injection site within the tubing allows various medications to be selectively infused into the blood vessel of the patient by the addition thereof to the solution flowing from the solution bag into the blood vessel via the upper tubing segment, injection site, lower tubing segment and introducer needle. This supplemental infusion is typically accomplished through the utilization of a conventional syringe, the needle of which pierces and is extended through the diaphragm disposed on the top end of the main body portion of the injection site. Subsequent to the expulsion of the medication from within the syringe and into the flowing solution, the needle is retracted out of the main body portion of the injection site, with the aperture created in the diaphragm due to the passage of the needle therethrough being substantially closed upon such retraction due to the resiliency of the diaphragm. As will be recognized, the incorporation of the injection site within the tubing allows various medications to be intravenously administered to the patient through the existing infusion site within the blood vessel, thus eliminating the need to subject the patient to additional needle sticks.
Though providing certain benefits to the patient, the injection sites constructed in accordance with the prior art possess certain deficiencies which detract from their overall utility. As previously explained, the use of such injection sites typically requires that the needle of the conventional syringe be extended through (i.e., puncture) the diaphragm attached to the top end of the main body portion of the injection site. However, the necessity of having to utilize a syringe with a needle to facilitate the introduction of the medication into the solution flow is undesirable due to the risk of inadvertent needle sticks.
In recognition of this deficiency, there has also been developed in the prior art needleless injection sites which incorporate a diaphragm adapted to assume open and closed configurations without having a needle inserted thereinto. Though these needleless injection sites eliminate the necessity of having to puncture the diaphragm with a needle, they also possess certain deficiencies which detract from their overall utility. Foremost of these deficiencies is the difficulty associated with disinfecting the injection site, and in particular the diaphragm thereof, subsequent to medication being infused thereinto. In this respect, after each use of the injection site the diaphragm must be cleaned, with such cleaning typically being accomplished through the application of alcohol or a similar disinfecting agent thereto. However, due to the configuration of the diaphragm, complete and effective disinfection thereof is often difficult to achieve, thus increasing the risk of the inadvertent introduction of contaminates into the solution stream upon subsequent uses of the injection site.
In an effort to overcome the deficiencies associated with the prior art injection sites, Applicant developed the needleless injection sites disclosed in the previously identified issued patents and co-pending applications which are the parent cases of the present application. The present needleless injection site constitutes an improvement over those disclosed in the parent cases. In this respect, the present injection site is provided with design features which are adapted to prevent the inadvertant obstruction of the fluid flow path, and to increase the level of positive flow within the fluid flow path such that the withdrawal of a needled or non-needled introducer from within the injection site does not cause a vacuum to be pulled within a tubular fluid line connected thereto.